Water-tube boiler.



W. R. WOOD.

WATER TUBE BOILER.

APPLIcMxoN FILED 0Ec.2e ,191s.

Patented Apr. 8, 1919.

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l owornebg WILFRED BOTHERY WOOD, 0F LONDON, ENGLAND.

WATER-TUBE "BOILEB,

Specification of Letters Patent.

Application led December 26, 1918. Serial No. 268,422.

To all lwhom it may concern:

Be it known that I, WILFRED Rornnny` Woon, a citizen of the UnitedStates of America,resident in London, England, have invented certain newand useful Improvements in Water-Tube Boilers, of which the` followingis a specification,

This invention relates to a vertical Wateri tube boiler of the kindhaving the tubes in compartments formed by vertical batlies radiatingfrom a central fiue or cylindrical baffle 'to a casing coaxial with theflue, the combustion gases passing down and up the compartments insuccession to the boiler flue.

The essential feature of this invention is a combination of the knownboiler having vertical Water tubes connected at the top and bot-tom endswith annular shaped drums, with the said arrangement of -the tubes incompartments, the cylindrical battle having at its upper part peripheralopenings the combined length of which in a horizontal plane amounts toat least one-third of the length of the periphery in ahorizontal plane,so that the gases enter some of the compartments and, having descendedthem, ascend others `on their way to the boiler iiue.

The invention is for the purpose of relievfing the boiler from strainsdue to. unequal heating and of working the boiler with less draft thanthe known construction requires. The boiler is smaller in over-alldimensions than boilers of this annular type having no tubecompartments. v

The boiler 'furnace is of substantially the same diameter as the annulardrums, but the combustion gases `are caused by a conical roof or arch tothe furnace, to iow through the central opening of the lowerannulardrum. The arch Iprotects this drum from the direct heat of thefurnace and provides an annular space between itself and the drum, whichspace is open to the compartments formed by the radial baffles andconstitutes a collecting chamber into which the dust carried by thedescending and ascending combustion gases settles and whence it canreadily be removed through a door in the casing of the boiler.

The superheater is placed within andv closes the central opening of theupper annular drum, a position of particular advantage, since itsheatingtubes depend into the combustion chamber or space, and the receivingcompartment of the superheater can be connected at more than one pointwith the steam space of the drum. This insures a uniform flow of steamthrough the superheater (particularly if the steam is taken from thedelivery compartment of the superheater at more than one point) andexcessive lloss of pressure is avoided. Preferably, the

superheater is of annular shape, its central opening being closedA by acover which can beremoved for obtaining access to the combustionchamber.

Since the depending tubes of the super- Patented Apr. 8, 1919.

heater are apt to be over-heated, it is preferable that some of thewater tubes should be arranged within the combustion chamber so thatsome of the heat may be removed from the gases before they leave thetubes of the superheater. This object is the better attained by soarranging such inner tubes that they form a constriction in thecombustion chamber.

To diminish further the iioor space re quired by the boiler the furnacehas a rotary grade of known kind, whereby the stoking can be eected fromone point and constant access to the boiler at any other Ipoint is notrequired.

Any of the usual means for feeding the drums may be employed. In theaccompanying drawings Figure l is a vertical section on line 1-1 of Fig.2, of a boiler yconstructed according to the invention, and Fig. 2 is ahorizontal section on line 2 2 ofFig. 1. y

The combustion chamber is formed by the cylindrical baille a' at theends of which are the annular water drums b, c respectively. The watertubes d which connect the drums are arranged on the perpheries of4imaginary' cylinders coaxial with cylinder a between the latter andAthe double-walled boiler casing e. These rows of tubes are grouped byvertical radial partitions f, whichextend to the upper drum butterminateat a short distance above the` lower drum to permit passage ofcombustion gases from one of the compartments formed by' lot extendinginto cylinder a.

partments as indicated by arrows m, beneath the partitions, up theintermediate compartments and through the passages left open to thechimney flue Z, as indicated by arrows ln..

r[he annular superheater o set in the annulus of drum b is of tubulartype, its tubes Its receiving chamber is connected by pipes 0 with thesteam space of drum b, and its delivery chamber has more than one steamofftake o2. To protect the superheater tubes from being over-heated thetwo inner rows of* water tubes are within the cylinder a and are soarranged as to produce a constriction in the combustion chambersubstantially following the dot and dash line a in Fig. l. In thismanner some of the heat of the combustion gases is taken up by the waterbefore the gases pass among the superheater tubes.

One method of producing such a throat or constriction in the combustionchamber consists in giving the row or rows of straight tubes d withinthe cylinder a the kind of arrangement which would be produced if 1 theywere set on the periphery of an imaginary cylinder between the waterdrums and one of the latter were rotated relatively to the other.Another method consists in curving the tubes within the cylinder asindicated in dotted lines at (Z3 in Figs. 1 and 2.

The circular grate p carrying rollersv p running on a circular track,and also carrying a circular rack (not shown), may be rotated by apinion (not shown) .engaging the rack and turned by hand as may berequired to bring the clinkers to the stoking door g, where fresh fuelmay =be substituted for them.

Air enters the upper part of the casing e at r and is drawn between thewalls of the casing to beneath the grate as indicated by arrows s and isthus preheated before it 'burns the fuel. l

The conical roof or arch v of the furnace is adapted to direct thecombustion gases into the central combustion chamber and to protect thelower annular dru'in from direct heat; it also forms with the casing aspace u below this drum from which dust may be removed through a door t.

The casing may also be provided with a number of doors such as fw forcleaning the outer surfaces of the tubes d, and a door m for access tothese tubes for removing them.

Access to the tubes d may be had by removing the cover y of the annularsuperheater o, and in order that these tubes (when they are of largerdiameter than ytubes d) may be removed, there is left inv A tubes d.This gap is opposite door a: so that ycross section with that sideflattened which forms the interior of the annulus, is adapted tofacilitate their construction without sacriicing their strength.

Having thus described the nature of the said invention andthe best meansI know of carrying the same into practical effect, l claim:

1. A boiler comprising, in combination, u per and lower annular waterdrums, upr1ght water tubes connecting said drums, a boiler casinginclosing said tubes and having an outlet, a cylindrical baiiieconstituting a substantially central combustion chamber, andsubstantially radial and vertical partitions subdividing the spacebetween said baiiie and the boiler casing into compartments eachcontaining a portion of said water tubes, said cylindrical baie havingat its upper end peripheral openings communicating with certain of saidcompartments, the remaining compartments being in communication withsaid outlet, the combined length of said openings in a horizontal planebeing equal to at least one third of the length of the periphery of saidbaille 1n a horizontal plane, and said partitions being arranged topermit passage of gases beneath them between adjacent compartments.

2. A boiler comprising, in combination, upper and lower annular waterdrums, upright water tubes connecting said drums, a oilercasinginclosing said tubes and having an outlet, a cylindrical baiieconstituting a substantially central' combustion chamber, andsubstantially radial 'and vertical partitions subdividing the spacebetween said bailie and the boiler casing into compartments eachcontaining a portion of said water tubes, said cylindrical baie havingat its upper end peripheral openings communieating withA alternatecompartments, the remaining compartments being in communication withsaid outlet,`the combined length of said openings in a horizontal planebein equal to at least one third of the length o the periphery of saidbaie in a horizontal plane, and said partitions being arranged to permitpassage of gases beneath them between adjacent compartments.

3. A boiler comprising, in combination, u per and lower annular waterdrums, upright water tubes connecting said drums, a boilercasing'inclosing said tubes and having an outlet, a cylindrical baiiieconstituting a substantially centra-l combustion chamber, a superheaterof the tubular type set within the annulus of thelupper drum with itstubes extending into said cylindrical baille, and substantially radialand vertical partitions subdividing the space between said baffle andthe boiler casing into compartments each containing a portion of saidwalter tubes, said cylindrical baille having at its upper end peripheralopenings communicating with certain of said compartments, the remainingcompartments being in communica-- tion with said outlet, the combinedlength of said openings in a horizontal plane being equal to at leastone third of the length of the periphery of said baille in a horizontalplane, and said partitions being arranged to permit passage of gasesbeneath them between adjacent compartments.

4. A boiler comprising, in combination, upper and lower annular waterdrums, upright water tubes connecting said drums, a boiler casinginclosing said tubes and having an outlet, a cylindrical baffleconstituting a substantially central combustion chamber, a superheaterof the tubular type set within the annulus of the upper drum with itstubes i extending into said cylindrical baille, certain of said watertubes being arranged within said baille to diminish the temperature ofthe combustion ases before they reach said superhea-ter tues, andsubstantially radial and vertical partitions subdividin the .spacebetween said baille and the boir casing into compartments eachcontaining a portion of lsaid water tubes, said cylindrical bafflehaving at its upper end peripheral openings communicating with certainof said compartments, the remaining compartments being in communicationwith said outlet, the combined length of said openings in a horizontalplane being equal to at least one third of the length of the peripheryof said baille in a horizontal plane, and said partitions being arrangedto permit passage of gases beneath them between adjacent compartments.

5. A boiler comprising, in combination, upper and lower annular waterdrums,- upright water tubes connecting said drums, a boiler casinginclosing said tubes and havmainil ing an outlet, a cylindrical bailleconstituting a substantially central combustion cham` ber, a superheaterof the tubular type set within the annulus of the upper drum with itstubes extending into said cylindrical bafle, a plurality of connectingpipes between the receiving space of said superheater and the steamspace of said upper drum, and substantially radial and verticalpartitions subdividing the space between said baille and the boilercasing into compartments each containing a portion of said water tubes,said cylindrical baille having at its upper endv peripheral openingscommunicating with certain of said compartments, the recompartmentsbeing in communica-- tion with said outlet, the combined length of saidopenings in a horizontal plane being equal to at least one third of thelength of the periphery of said baille in a horizontal plane, and saidpartitions being arranged Ito permit passage of gases beneath thembetween adjacent compartments.

6. A boiler comprising, in combination,

upper and lower annular .water drums, each of circular cro-ss sectionwith that side flattened which forms the interior of the annulus,upright water tubes connecting said drums, a boiler casing inclosingsaid tubes and having an outlet, a cylindrical baille constituting asubstantially central combustion chamber, and substantially radial andvertical partitions subdividing the space between said baille land theboiler casing into compartments each containing a portion of said watertubes, said cylindrical baille having at its upper end peripheralopenings communithe remaining compartments being in communication'withsaid outlet, the combined length of said openings in a horizontal planebeing equal to at least one third of the length of the periphery of saidbaille in a horizontal plane, and said partitions being arranged topermit passage of gases beneath them between adjacent compartments.

In testimony whereof I have signed my name to this specification.

IWILFRED RoTHERY woon.

`eating with certain of said compartments,

